An optimum design of antireflection coating for spherical silicon solar cells

Antireflection (AR) coatings for spherical crystalline silicon solar cells are theoretically optimized from the viewpoint of achieving the largest photon densities in the spherical crystalline silicon solar cells. Because the AR film thickness is optimized with regard to the photon densities in the spherical crystalline silicon solar cells, tolerance in the film thickness can be evaluated. Also, the optimized AR film thicknesses for the spherical crystalline silicon solar cells and planar crystalline silicon solar cells are compared, and analytic expressions for the optimized AR film thicknesses are derived as a function of a quarter-wavelength film thickness.     

1,8-Cineole Ameliorates Steatosis of Pten Liver Specific KO Mice via Akt Inactivation

Hepatocyte-specific Phosphatase and tensin homolog (Pten)-knockout (KO) mice exhibit hepatic lesions analogous to non-alcoholic steatohepatitis (NASH). 1,8-cineole is a monoterpene oxide and it has several biological effects including hepatoprotective effects. In this study we revealed that 1,8-cineole ameliorates NASH of Pten KO mice. Pten KO mice were assigned to a control group without any medication or to a 1,8-cineole group injected with 50 mg/kg i.p. twice per week for eight weeks. At eight weeks, livers from each group were processed to measure triglyceride (TG) content, gene expression analysis, western blot analysis, and histological examination including Oil red O staining. 1,8-cineole ameliorated hepatic steatosis in Pten KO mice, revealed by TG content and Oil red O staining. Moreover, 1,8-cineole downregulated collagen 1a1 expression and improved liver fibrosis. Thus, 1,8-cineole has potential as a candidate to treat NASH by inactivating the Akt/PI3-kinase pathway.     

Frictional properties of diamond-like carbon coated tool in dry intermittent machining of aluminum alloy 5052

In this study, an orthogonal intermittent machining test for aluminum alloy 5052 was conducted under dry conditions. By using cutting forces that were measured during the test, the frictional properties of a tool rake face were evaluated during intermittent machining for two types of diamond-like carbon (DLC)-coated tools and an uncoated carbide tool. DLC films used in the test were composed of tetrahedral amorphous carbon (ta-C) deposited by a filtered arc deposition process and hydrogenated amorphous carbon (a-C:H) deposited by a plasma-enhanced chemical vapor deposition process. The test results showed that the initial friction coefficients were approximately 0.8 for all tools. However, with increasing machining time, the friction coefficient of only the ta-C-coated tool decreased remarkably to a lower value of 0.3, whereas those of the a-C:H-coated tool and the uncoated carbide tool remained high. An electron probe micro analyzer (EPMA) analysis revealed an area where no aluminum adhered on the ta-C-coated tool rake face after intermittent machining. This area provided low frictional properties during intermittent machining. An X-ray photoelectron spectroscopy (XPS) analysis showed that the carbon bonding of the DLC film surface in this area had changed from the state before machining.     

Pose Estimation of Construction Materials Using Multiple ID Devices for Parts and Packets Unification

Abstract: A method for characterizing the pose (position and orientation) of large objects using multiple identification (ID) devices, such as radio‐frequency identification (RFID) devices, is proposed. Simultaneous management of construction materials and their data using ID devices for construction automation has been proposed. In this management scheme, workers or robots (1) acquire the ID of a device using an ID reader, (2) obtain construction material data using the ID, and (3) use the data to perform various tasks. In this scheme, the object pose is crucial because it can be changed by robots and workers who do not possess an ID reader or have not measured the pose previously. The proposed method uses the geometric relationship between the ID device attached to the object and the ID reader, and is based on the relationship between the relative displacements of multiple ID devices. The position and direction of each ID device and ID reader are measured with respect to the object and reference coordinate frames, respectively. Experimental results proved the feasibility of our proposed method.     

Electric conduction of PbBr-based layered perovskite organic–inorganic superlattice having carbazole chromophore-linked ammonium molecule as an organic layer

We have successfully prepared thin films of PbBr-based layered perovskite having hole-transporting carbazole chromophore-linked ammonium molecules as an organic layer by a simple spin-coating from the N,N-dimethylformamide solution in which the stoichiometric amount of lead bromide and carbazole-linked ammonium bromides was dissolved. Their X-ray diffraction profiles exhibited that their layer structure formed (0 0 n)-orientation, where c-axis is perpendicular to the substrate plane. Their layer structure depended on the alkyl chain length of ammonium molecules. When methylene length of C₅H₁₀ was employed in the carbazole-linked ammonium molecules, highest orderliness of the layer structure was attained; higher-order X-ray diffraction peaks were observed in the layered perovskite films. In the layered pervskite film, in-plane conduction, namely conduction in the direction of the stacking of carbazole chromophore, was measured. For comparison, conductivity of poly(N-vinylcarbazole) (PVCBz) thin film was also measured. The conductivity of the layered perovskite thin film (1.8 × 10^?10 Scm^?1 at 303 K) was about three order of magnitude larger than that of the PVCBz thin film (5.3 × 10^?14 Scm^?1 at 303 K). Despite the much higher conductivity of the layered peroskite thin film, the activation energy of the conductivity of the layered perovskite thin film (1.44 eV) was about 2.4 times larger than that of the PVCBz thin film (0.61 eV). This phenomenon is probably due to difference in film morphology through considering the results of AFM observation.     

Estimation of modeling approximation errors using data assimilation with the minimum variance approach

In this paper, we estimate prediction errors owing to approximations in calculation models (modeling approximation error) using the data assimilation method. Correlations between the modeling approximation error and neutronics parameters obtained through calculations are evaluated in test configurations and then the evaluated correlations are used to predict the modeling approximation errors in design configuration. Formulae to estimate the modeling approximation error using the correlations are derived based on the minimum variance approach and the physical interpretation of the formulae is discussed through simple cases. The proposed method is applied in 2 × 2 and 3 × 3 fuel assembly geometries using specifications of the KAIST benchmark problem. The correlation between the modeling approximation error and parameters (neutron leakage in each fuel assembly) is estimated in 2 × 2 fuel assemblies and then the modeling approximation error in 3 × 3 fuel assemblies is predicted using the correlation. The calculation results not only indicate feasibility of the present method, but also suggest a need for further investigation on the assumptions used in the present study, i.e. applicability and robustness of the correlation among different geometries.     

The effects of assistive walking robots for health care support on older persons: a preliminary field experiment in an elder care facility

Intelligent Service Robotics - In the present research, we prepared a human-size humanoid that autonomously navigates alongside with a walking person. Its utterances were controlled by Wizard-of-Oz...     

Synthesis and photoluminescence properties of fluorine-containing poly(phenylene vinylene) bearing hexafluorocyclopentene-fused phenanthrene unit

The intramolecular oxidative photocyclization of 1,2-diarylhexafluorocyclopentene ( 1 ) under light irradiation (λ = 365 nm) provided hexafluorocyclopentene-fused phenanthrene with formyl groups ( 2 ) in moderate yield. The copolymerization of 2 with tetraethyl(2,5-bis(dodecyloxy)-1,4-phenylene)bis(methylene)diphosphonate by the Horner–Wadsworth–Emmons reaction gave a fluorine-containing poly(phenylene vinylene), Polymer-2, in 41% yield. For comparison, a diphenylethene-type copolymer, Polymer-1, was also prepared analogously. The number-average molecular weights of Polymer-1 and Polymer-2 were 8900 and 3300 g mol^?1, respectively. The copolymers showed high thermal stability, as revealed by their thermogravimetric analysis. UV–visible spectra of the copolymers in CHCl₃ showed π–π* transition peaks at around 420 nm, and the peaks shifted to longer wavelengths by ca 10 nm for samples in film form. The photoluminescence spectra of Polymer-1 and Polymer-2 exhibited peaks at 542 and 560 nm in CHCl₃, respectively, whereas the photoluminescence intensity of Polymer-2 was very low in the solid state, presumably owing to the partial aggregation of the polymer molecules. © 2021 Society of Industrial Chemistry.